Numerous protective covers have been proposed for use on shackle padlocks (see U.S. Pat. Nos. 3,848,440; 4,244,813; and 4,317,344). These covers are positioned on the locks for the purpose of preventing (or reducing) the entry of contaminants into the lock through the keyhole opening.
Other sealing proposals have been made known to the industry for the purpose of sealing the openings in the lock body through which the shackles reciprocate during operation (see U.S. Pat. Nos. 2,375,458 and 2,904,985).